Pasternak, Jeffrey J.

Background Outcome selection in regional anesthesia and acute pain research is inconsistent, often lacking patient-centered priorities and validated instruments. We aimed to prioritize key outcomes and propose suitable measurement tools to improve the quality, consistency, and relevance of regional anesthesia research. Methods We conducted a multiround Delphi process, including two electronic voting rounds, a multiday in-person meeting, and a patient panel. Experts and patients evaluated existing and proposed outcomes for importance, validity, and relevance. Outcomes reaching ≥70% agreement were prioritized, and appropriate measurement instruments were identified. Results Thirty-two experts and three patients participated. Across three Delphi rounds, 10 outcomes were prioritized for future regional anesthesia research: seven efficacy outcomes (pain scores; opioid consumption; Brief Pain Inventory; functional outcomes; cognitive function; length of stay; block duration); two multidimensional outcomes (quality of recovery and development of a regional anesthesia-specific quality-of-recovery instrument); one safety outcome (chronic postsurgical pain). Patients prioritized cognitive recovery, function, chronic pain, and pain scores. Conclusions This consensus-based, patient-centered framework defines the core priorities for future regional anesthesia and acute pain research. Future work should focus on developing and validating a regional anesthesia-specific quality-of-recovery instrument, refining multidimensional measures such as functional recovery, cognitive outcomes, and the Brief Pain Inventory, and standardizing the reporting of chronic pain and opioid-related outcomes. Adoption of these priorities will enhance methodological consistency, comparability, and patient relevance in future clinical trials.

BACKGROUND AND OBJECTIVES: Venous air embolism (VAE) can cause significant morbidity and mortality. Prevention and management of VAE include cessation of air entrainment, positioning changes, and hemodynamic support. The degree to which position change and cardiac output (CO) moderate resolution of intracardiac air has not been rigorously studied using contemporary transesophageal echocardiography (TEE). METHODS: This observational cohort-type study aimed to identify the effect of supine vs sitting positioning on the movement and resolution of intracardiac air. In 20 patients undergoing seated neurosurgery, central venous air aspiration catheters were placed through the median basilic vein. TEE was used to estimate the time required for clearance of agitated microbubbles from the right atrium and ventricle in both the supine and sitting position. Estimates of CO were also obtained echocardiographically in each position. RESULTS: Average clearance time was faster in the sitting vs the supine position with no significant difference in CO. A negative correlation between CO and right atrial clearance time across all patients was demonstrated with a Pearson coefficient of −0.4 (95% CI −0.07, −0.65) with P = .02. CONCLUSION: During VAE, both patient position and CO can significantly affect how bubbles move through intracardiac chambers. However, augmenting CO during VAE may be clinically more feasible, efficient, and productive than changing positioning—especially during crises unless the changing in position is intended to halt the entrainment of air. Further TEE studies of intravascular air movement affected by other position changes (lateral, reverse Trendelenburg) and vasopressors should be considered.

Motor-evoked potential (MEP) monitoring is an electrophysiologic technique useful for testing peripheral motor nerve integrity during cryoablation cases with risk of nerve injury. Previously, neuromonitoring within the magnetic resonance imaging (MRI) suite for cryoablation has not been performed as magnetic needles are used which could cause magnetic field interactions with neuromonitoring leads. We present the first report of a patient who underwent MEP monitoring during MRI-guided cryoablation of a vascular malformation adjacent to the brachial plexus. We demonstrate that MEPs may be safely and accurately performed by interleaving MRI and MEPs during treatment, reducing the risk of postprocedural complications.

Remimazolam is a novel ultrashort-acting benzodiazepine that produces sedation by acting as a positive allosteric modulator of the gamma-amino butyric acid-A receptor. Its high water solubility and metabolism via tissue esterases allow for a rapid onset of sedation/anesthesia and prompt arousal despite prolonged use. In addition, the effects of remimazolam can be reversed with flumazenil. This narrative review discusses the role of remimazolam in patients undergoing neurosurgical and neuroradiological procedures, specifically its role during awake craniotomies and compatibility with neuromonitoring. Considerations for remimazolam use in patients with neurological diseases are also highlighted. In addition, the impact of remimazolam on postoperative excitation, risk for postoperative delirium, and delayed neurocognitive recovery are discussed. Although there seems to be a clinical promise for remimazolam based on limited case studies and our own institutional experience of its use, further clinical investigation is warranted to understand the potential impact of remimazolam on surgical and neurological outcomes.

Background: Despite advances in perioperative neuroscience, there is low interest among anesthesiology trainees to pursue subspecialty training in neuroanesthesiology. We conducted a pilot survey to assess attitudes about neuroanesthesiology fellowship training. Materials and Methods: A confidential survey was distributed to an international cohort of anesthesiology attendings and trainees between January 15, 2017 and February 26, 2017. Results: A total of 463 responses were received. Overall, 309 (67%), 30 (6%), 116 (25%), and 8 (2%) of respondents identified themselves as attendings, fellows, residents, and “other,” respectively. In total, 390 (84%) of respondents were from the United States. Individuals typically pursue anesthesiology fellowship training because of interest in the subspecialty, acquisition of a special skill set, and the role of fellowship training in career planning and advancement. Overall, 64% of attendings, 56% of fellows, and 55% of residents favored accreditation of neuroanesthesiology fellowships, although opinion was divided regarding the role of accreditation in increasing interest in the specialty. Respondents believe that increased opportunities for research and greater exposure to neurocritical care and neurological monitoring methods would increase interest in neuroanesthesiology fellowship training. Perceived barriers to neuroanesthesiology fellowship training were perceptions that residency provides adequate training in neuroanesthesiology, that a unique skill set is not acquired, and that there are limited job opportunities available to those with neuroanesthesiology fellowship training. Conclusions: In this pilot survey, we identified several factors that trainees consider when deciding to undertake subspecialty training and barriers that might limit interest in pursuing neuroanesthesiology subspecialty training. Our findings may be used to guide curricular development and identify factors that might increase interest among trainees in pursuing neuroanesthesiology fellowship training.

Background: Physiological alterations during the perianesthetic period may contribute to secondary neurocognitive injury after a concussion. Methods: Patients exposed to concussion and who received an anesthetic within 90 days were matched to unexposed patients without concussion. Intraoperative and postoperative events were compared. Subgroup analyses assessed relationships among patients with a concussion in the prior 30, 31 to 60, and 61 to 90 days and their respective unexposed matches. To facilitate identification of potential targets for further investigation, statistical comparisons are reported before, as well as after, correction for multiple comparisons. Results: Sixty concussion patients were matched to 176 unexposed patients. Before correction, 28.3% postconcussion versus 14.8% unexposed patients reported postanesthesia care unit pain score≥7 (P=0.02); 16.7% concussion versus 6.5% unexposed patients reported headache within 90 days of anesthesia (P=0.02) and 23.5% of patients who received surgery and anesthesia within 30 days of concussion experienced headache within 90 days of anesthesia compared with 7.1% in the unexposed group (P=0.01). Patients who experienced concussion and had anesthesia between 31 and 60 days after injury had a postanesthesia care unit Richmond Agitation and Sedation Scale score of −1.61±1.29 versus a score of −0.2±0.45 in unexposed patients (P=0.002). After adjusting the P-value threshold for multiple comparisons, the P-value for significance was instead 0.0016 for the overall cohort. Our study revealed no significant associations with application of adjusted significance thresholds. Conclusions: There were no differences in intraoperative and postoperative outcomes in patients with recent concussion compared with unexposed patients. Before correction for multiple comparisons, several potential targets for further investigation are identified. Well-powered studies are warranted.

Background: Positive-pressure myelogram (PPM) is an emerging radiologic study used to localize spinal dural defects. During PPM, cerebrospinal fluid pressure (CSFp) is increased by injecting saline with contrast into the cerebrospinal fluid. This has the potential to increase intracranial pressure and compromise cerebral perfusion. Methods: We performed a retrospective chart review and analysis of 11 patients. The aim was to describe the periprocedural anesthetic management of patients undergoing PPM. Results: All patients underwent PPM with general anesthesia and intra-arterial blood pressure and near-infrared spectroscopy monitoring of regional cerebral tissue oxygen saturation. Mean±SD maximum lumbar CSFp was 58±12 mm Hg. Upon intrathecal injection, mean systolic blood pressure increased from 115±21 to 142±32 mm Hg (P<0.001), diastolic blood pressure from 68±12 to 80±20 mm Hg (P≤0.001), and mean blood pressure from 87±10 to 98±14 mm Hg (P=0.02). Ten of 11 patients received blood pressure augmentation with phenylephrine to minimize the risk of reduced cerebral perfusion secondary to increased CSFp after intrathecal injection. The mean heart rate before and following injection was similar (68±15 vs. 70±15 bpm, respectively; P=0.16). There was a decrease in regional cerebral oxygen saturation after positioning from supine to prone position (79±10% to 74±9%, P=0.02) and a further decrease upon intrathecal injection (75±10% to 69±9%, P≤0.01). Conclusions: Systemic blood pressure increased following intrathecal injection during PPM, possibly due to a physiologic response to intracranial hypertension/reduced cerebral perfusion or administration of phenylephrine. Regional cerebral oxygen saturation decreased with the change to prone position and further decreased upon intrathecal injection. Cerebral near-infrared spectroscopy has a potential role to monitor the adequacy of cerebral perfusion and guide adjustment of systemic blood pressure during PPM.

BACKGROUND: We evaluated the hypothesis that the rate of postoperative decline in global cognition is greater in older adults exposed to general anesthesia with nitrous oxide (N 2 O) compared to general anesthesia without N 2 O. METHODS: Longitudinal measures of cognitive function were analyzed in nondemented adults, 70–91 years of age, enrolled in the Mayo Clinic Study of Aging. Linear mixed-effects models with time-varying covariates assessed the relationship between exposure to surgery with general anesthesia (surgery/GA) with or without N 2 O and the rate of long-term cognitive changes. Global cognition and domain-specific cognitive outcomes were defined using z scores, which measure how far an observation is, in standard deviations, from the unimpaired population mean. RESULTS: The analysis included 1819 participants: 280 exposed to GA without N 2 O following enrollment and before censoring during follow-up (median [interquartile range {IQR}] follow-up of 5.4 [3.9–7.9] years); 256 exposed to GA with N 2 O (follow-up 5.6 [4.0–7.9] years); and 1283 not exposed to surgery/GA (follow-up 4.1 [2.5–6.4] years). The slope of the global cognitive z score was significantly more negative following exposure to surgery/GA after enrollment (change in slope of −0.062 [95% confidence interval {CI}, −0.085 to −0.039] for GA without N 2 O, and −0.058 [95% CI, −0.080 to −0.035] for GA with N 2 O, both P < .001). The change in slope following exposure to surgery/GA did not differ between those exposed to anesthesia without versus with N 2 O (estimated difference −0.004 [95% CI, −0.035 to 0.026], P = .783). CONCLUSIONS: Exposure to surgery/GA is associated with a small, but statistically significant decline in cognitive z scores. Cognitive decline did not differ between anesthetics with and without N 2 O. This finding provides evidence that the use of N 2 O in older adults does not need to be avoided because of concerns related to decline in cognition.